Manually adjustable time delay means



Dec. 16, 1941. c. M. OSTERHELD MANUALLY ADJUSTABLE TIME DELAY- MEANS F iled Oct. 4, 1940 3 Sheets-Sheet l INVENTOR CL A Rk M 05 TER/IELD ATTORNEY Dec, 16, 1941.

c. OSTERHELD MANUALLY ADJUSTABLE TIME DELAY MEANS Filed Oct. 4, 1940 3 Sheets-Sheet 2 INVENTOR CLARk OSTER/IELD AT T ORNEY Dec. 16, 1941. c. M. OSTERHELD 2,266,244

MANUALLY ADJUSTABLE TIME DELAY MEANS Filed Oct. 4, 1940 I5 Sheets-Sheet 3 v Z25 A97 /65 2/0, /6.5 253 INVENTOR I CLARk 0575mm!) 43 r 7 BY a/ 51 ATTORNEY Patented Dec. 16, 1941 MANUALLY ADJUSTABLE TIME DELAY MEANS Clark M. Osterheld, Stoughton, Wis., assignor to McGraw Electric Company, Elgln, 111., a corporation of Delaware Application October 4, 1940, Serial No. 359,741

13Claims.

My invention relates to electric water heating systems and particularly to oil-peak water heating systems.

One of the objects of my invention is to provide an off-peak water heating system having means therein whereby a user can cause a predetermined delay in the energization of the electric tank heater after the start of an off-peak period.

Another object of my invention is to provide a main heater control switch adapted to be closed at the beginning of an off-peak period and to be opened at the end of an off-peak period by a continuously operative timing means in combination with means for manually and mechanically effecting delay in the energization of the heater at the will of an operator.

Another object of my invention is to provide an off-peak water heating system including a manually-actuable energization-delay means that will prolong the energization of the heater beyond the end of the oil-peak period at the desire of the operator or user of such a-water heating system.

In the drawings, I Figure l is a view in vertical section through a hot water tank having my improved hot water heating system associated therewith and views showing the continuously operative timing means and the manually-adjustable delay means together with the circuit connections therebetween,

Fig. 2 is a view in front elevation of a casing containing the main parts of the delay-eifecting means therein,

Fig. 3 is a view in side elevation of the device shown in Fig. 3,

Fig. 4 is a view in vertical section therethrough taken on the line 4-4 of Fig. 5,

Fig. 5 is a view in vertical section taken on the line 5-5 of Fig. 4,

Fig. 6 is a partial view of my improved water heating system showing more particularly the electrical circuit connections of a modified form,

Fig. 7 is a view similar to Fig. 6 but showing a still further modification thereof, and,

Fig. 8 is a view similar to Figs. 6 and 7 but showing a still further modification embodying my invention.

The use of a heater control switch mechanically actuated to closed and to open positions at predetermined times of a day of twenty-four hours, is already well known. My invention adds to this old and known device and means for controlling the energization of an electric tank heatby an operator or user can cause a delay in the energization of the electric heater beyond the start of an off-peak period at his own will in order to ensure that the main part of the heating period provided by my improved system will occur during the hours when the station load during the oil-peak period is substantially at. its minimum. Effective at the will of the operator control means in the system may be moved to effective position to cause an over-run or prolongation oi the energization of the heater if desired and in case all of the water in the tank is not hot or has not been heated to a predetermined hot water temperature. It is also possible for the user of a system embodying my present invention to easily and quickly adjust the system to prevent energization of the heater during oil-peak periods as may be desirable in case the owner or user of the system is to be away from the home or other establishment in which the system is located for some appreciable time, so that energization of the heater is prevented until the return of the owner or user.

Referring first to Fig. 1 of the drawings, I have there illustrated a continuously operative timing device I l which includes, among other elements, a synchronous motor l3 which is energized from the same circuit whichenergizes the other parts of the system and particularly the electric heater associated with a hot water tank. The motor l3 has a worm gear IS on its shaft meshing with a worm wheel ll mounted on a shaft H which shaft I! has mounted thereon a cam disc II the major part of the periphery of 7 which is of a given radius but the other part of which is of larger outer radius, as shown by the numeral 23 and it is to be understood that the peripheral extent of this portion 23 of larger outer radius may be made variable or adjustable and is of a length corresponding to the desired oil-peak period. It may be noted that I have shown an eight-hour oil-peak period comprehended within the beginning and the end of the portion 23.

I provide a timer-actuated heater control switch 25 shown generally only as comprising a relatively rigid contact arm 26, a resilient contact arm 21 and a resilient contact arm 29 normally biased out of engagement with arms 26 and 21 but moved into such engagement by the cam portion 23 during the off-peak period. It will, therefore, be noted that the contacts of switch 25 are normally in engagement with each er, relatively simple and effective means where- 53 othe d ring the off-peak period and that they are out of engagement during the rest of the twenty-four hour day.

A hot water tank 3| is provided with a cold water inlet pipe 33 and a hot water outlet pipe 35 and the tank 3| may be heat-insulated by a surrounding mass 31 of any suitable heat-insulating material now used for such purposes and an outer-casing 39 may be providedto protect the mass 31. The tank structure may be supported as by a plurality of legs 4|, all in a manner well known in the art. An electric tank heater 43 encircles the tank 3| near the lower end thereof and may be located within a tunnel member 45 and, merely for purposes of illustration, reference may here be made to the'electric tank heater disclosed and claimed in my copending application Serial No. 284,881 filed July 17, 1939. I do not desire, however, to be limited to this construction of electric tank heater but may use any other type of heater.

An electromagnetic contactor 41 including fixed contacts and a movable contactbridging member is provided, the contacts of which are connected in electric series circuit relatively to the timer controlled heater switch 25 and 1pmvide further a thermal heater control switch 49 which, for illustrative purposes, is shown as comprising two contact arms 5I and '53 normally biased into engagement and controlled by a'n'ex pansion rod mounted within a tubular member 51 to the effect that contact arms 5i and 53 will be in engagement when the tubular member 51 is subject to the temperature of cold water or of water whose temperature is below a predetermined value, expansion of rod 55 causing disengagement of resilient" contact arm 53 from the relatively rigid arm 5| when'the water surrounding tubular member 51 is hot or when its temperature is above a predetermined adjustable value. I desire to point out that a thermallyactuable switch of the kind shown in Fig. 1 of the drawings has been shown for illustrative purposes only and that any other thermally-actuable switch effective for the same purpose and operating in the same manner may be used by me. It may be here pointed out that when the timer controlled switch 25 is closed and when the contacts of 'contactor 41 are engaged by the contact bridging member and when the thermally-actuable switch 49 is closed, the heater 43 will be of day.

Means for manually causing a delay in the energization of the heater 43 after thestart of the off-peak period includes a casing 63 mounted 6 on a base 65 which is provided with any suitable or desired means to permit of mounting the easing and apparatus contained therein in any desired place at the will of the user of a system of this kind which may, for instance, be on one wall of a kitchen. I desire to point out that the location of the casing 33 should be such as can easily be seen by, the user of a water heating system of this kind so that the desired adjll stments which may be made from day to day can be made easily and quickly.

The base 65 has mounted thereon a. short stud 61 fixed centrally of the circular base which stud has mounted thereon a gear wheel 69 integral and mounted on and at one end of, an elongated sleeve 1|. thereon a gear wheel 13 which has integral therewith a relatively small pinion 15 which pinion meshes with a spur gear wheel 11 rotatably mounted on a short stud 19 carried by the base 65. The gear wheel 11 has integral therewith a. small pinion 8| which meshes with the gear wheel 69. Also mounted on bushing II is a cam disc 83 fixed on the bushing 1| and therefore rotatable therewith. Reference to Fig. 4 of the drawings will show that the cam disc 83 is provided with two relatively short portions 35 and 81 of larger outer radius while the main portion of the disc 83 is of uniform outer radius. The cars 85 and 81 are positioned diametrically opposite to each other and it is to be noted that cam disc 83 is rotated through 180 during'an off-peak period.

An electric motor 88 of any suitable or desired kind and shown schematically only in Figs. 1, 4 and 5 of the drawings is supported as on the base 65 and carries a small pinion 89 on its shaft which pinion mesheswith gear wheel 13 to cause rotation thereof when motor 88 is energized, as will be hereinafter described.

A manually-actuable knob or button 9! is positioned in front of the front wall of casing 63 and is fixedly mounted on a tubular bushing member 93 which bushing member has integral therewith an arm 95 extending substantially radially from the bushing 93. A switch is insulatedly mounted on the outer end of arm 95 and includes an outer substantially rigid contact arm 91 and an inner resilient contact arm 99, a block I9! of electric insulating material insulating the contact arms 91 and 99 from each other as well as-from the arm 95, It is here to be noted that arm 91 is longer than arm 99 for a purpose which will hereinafter appear. A stop pin I03 is fixedly mounted in base 65 at a predetermined point to limit the turning movement of arm 95 in a counter-clockwise direction. The contact arms 91 and99 are shown as being in engagement in Figs. 1 and 4 of the drawings when projection 85, for instance, is in engagement with a lug I05 on arm 99 to thereby cause closing of the switch including arms 91 and 99. It will be noted that an operator can turn knob 9| in a clockwise direction through any desired distance so that while the normal position at the beginning of an ofi-peak period of the cam 83 is that shown in Fig. 4 of the drawings, the arm 95 maybe moved to some other position, as will be hereinafter described in detail. The front wall of casing 63 is provided with an arcuate opening 101 therein which has a transparent closure member I09 and a suitable clamping means- III in back of the glass or other transparent material I09 to hold the same to close opening I01, Member I09:may have mounted thereon or show a plurality of numerals shown in Fig. 2 ofthe drawings as including 10, 11, 12, 1, 2, 3, 4, 5 and at the ex treme right-hand end portion thereof, the word "011 An arrow H3 may be provided on arm 95 or on any other part fixed relatively tothe arm 95 so that the operator may know what setting of arm 95 he has accomplished by turning movement thereof.

I provide an additional electromagnetic con- The sleeve 1| has rotatably mounted tactor III which includes a pivotally mounted contact arm I I1 which normally is in the position shown in Fig. 4 of the drawings where'it will engage a fixed contact member II9, this position being shown by the broken lines in Fig. 1 of the drawings. When the coil of contactor II5 is energized, arm II1 will be energized and attracted to the position shown by the full lines in Fig. 1 of the drawings where it will engage a second fixed contact member I2I.

The structure of contactor II5 carries an auxiliary control switch including relatively rigid contact arm I23 and a resilient contact arm I25 which is normally biased into engagement with arm I23.

The electric circuit connections are substantially as follows: Supply circuit conductor 9| is connected to contact arm 29 while contact arm 21 is connected by a conductor I21 to one of the fixed contact members of contactor 41, the other fixed contact of contactor 41 being connected to contact bar 5I of thermal switch 49 by a conductor I29. A conductor I3I connects contact arm 53 with the heater 43 while the other end of heater 43 is connected by a conductor I33 to supply circuit conductor 59. A conductor I34 connects contact arm 26 to one terminal of motor 99 and a conductor I 31 connects the other. terminal of motor 88 to conductor I33 so that motor 98 will be energized upon engagement of contact arms 29 and 21 with contact arm. 'at the start of an off-peak period to cause the motor 39 to operate and to cause turning movement in a clockwise direction of cam disc 93. A conductor I35 extends from conductor I21 to contact arm 99 and a conductor I39 connects contact arm 91 with one terminal of the coil of contactor H5 and also connects with fixed contact member I2 I A conductor I4I connects conductor I21 to contact arm II1. A conductor I43 connects fixed contact member H9 with one terminal of the coil of contactor 41 the other terminal of which is connected by a conductor I45 with conductor I33 and thereby to the other supply circuit conductor 59. A conductor I41 connects the other terminal of the coil of contactor II5 to contact arm I23 and contact arm 125 is connected by a conductor I49 with conductor I31.

member of contactor 41 will be in the position shown in the full lines in Fig. 1 of the drawings whereby heater 43 will be energized by the cooperative and joint action. of switch 25, the con- Let it be assumed that the user of a particular water heating system of the kind shown in Fig. l of the drawings desires to have the heater 43 energized at the start of the off-peak period in which case he will either move the arm 95 into the position shown in Fig. 1 of the drawings or will leave it in such position if it was positioned therein at some earlier time. As soon as the cam disc 2I of the continuously operative timing means II has caused closing of the triple arm switch 25, a current will fiow from supply circuit lead 6i through switch 25, conductor I34, through electric motor 88 and back through conductor I31 to the other supply circuit 59 causing operation of the motor. Another circuit is closed from lead 5|, switch 25, through conductors I21 and I35, contact bars 99 and 91, in engagement with each other at that time, conductor I39, the coil of contactor I I5, conductor I41, contact arms I23 and I25 which are in engagement with each other, conductors I49, I31 and I33 to the other supply circuit lead 59. This energized contactor II5 causing the pivotally mounted contact arm II1 to move into the position shown by the full lines in Fig. 1 of the drawings thereby deenergizing or preventing energization of contactor 41 with the result that the contact bridgin tacts of contactor 41 and of the thermal switch 49 in case of the presence of an appreciable amount of cold water in the tank 3I at the start of an off-peak period.

While I have shown a particular position of the thermal switch 49, it is obvious that I may change this position but in general, in a system of this kind, I prefer to have the thermal switch 49 cause opening of its contacts when the tank is substantially full of hot water.

Let it now be assumed that the arm was adjusted prior to the time of closure of switch 25 by the continuously operative timing means, to a position where the pointer II3 was opposite the numeral 2, that is, the user desired to retard or delay energization of the heater 43 for a period of four hours. The position of the contact arms 91 and 99 will then be as shown by the broken lines in Fig. 1 of the drawings and the circuit through the contact arms 91 and 99 and through the coil of contactor II5 will not be closed at the start of the oil-peak period as was hereinbefore described for other operating conditions clearly pointed out. In this case, that is, with the coil of contactor II5 unenergized, contact arm II1 controlled thereby will be in im lower position as shown by the broken lines in Fig. 1 of the drawings whereby it will engage fixed contact member H9 and provide an energizing circuit for the coil of contactor 41 substantially as follows: From supply circuit lead 6| through switch 25, conductor I21, conductor I, contact arm II1 to contact II9, through conductor I43 and the coil of contactor 41, and then through conductors I45 and I33 to the other supply circuit lead 59 this causing energization of the contactor with resultant upward movement of the bridging member of contactor 41 to the position shown by broken lines in Fig. 1 of the drawings whereby the heater energizing circuit is interrupted at this particular place. If the contact arms 91 and 99 on the adjustable arm 95 were moved to the position shown by the broken lines in Fig. 1 of the drawings they will be caused to move into engagement with each other at substantially two oclock a. m. at which time the coil of contactor II5 will be energized, as was hereinbefore described, to cause movement of the arm I "in an upwardly direction thereby deenergizing the coil of contactor 41 and'causing closure of the heater circuit by the contactor 41 as hereinbefore described.

It is to be further pointed out that the contact arms 91 and 99 are to be held in engagement with each other during a relatively short period, say a few seconds only, when one of the ears 95 or 91 engage arm 99 but that it is desired to continue the energization of the coil of contactor II5, which is effected as follows: Upon engagement of contact arm I I1, with contact I2I a holding circuit is closed through conductor I4I, contact bar H1, contact member I2I, conductor I39 to the coil of contactor I I5, through conductor I41, contact bar I23 and contact bar I25 and then through conductors I49 and I31 to the other supply circuit lead whereby the disengagement of contact arms 91 and 99 from each other will not change the condition of contactor II5 but it will continue until opening of the switch 25 by the timing means at the end of an oil-peak period will deenergize the entire circuit including, of course, the electric heater 43.

If the user of an improved system of the kind disclosed and claimed desires to deenergize the heater control system beyond the time controlled by the continuously operative timing means as in case the user'of a domestic system of this kind goes on a vacation, he may do so in the following manner: By turning movement on the knob 9I with resultant turning movement in a clockwise direction of arm 95 and the switch contacts carried thereby to an extreme position where arm 95 will engage with a fixed stop pin I5I (see Fig.

1) the elongated contact arm 91 is adapted to engage an insulating block I53 on contact arm I25 to thereby cause disengagement of contact arm I25 from contact arm I23 whereby the control circuit through the coil of contactor H5 is permanently opened. It is evident that under these conditions closure of switch 25 by the timing device will have no effect upon the rest of the system since the contact arm II1 remains in engagement with fixed contact member I I9 whereby the heretofore described energizing circuit through the coil of contactor 41 remains closed during the time that switch 25 is closed whereby the energizing'circuit of the heater is interrupted at the contacts of contactor 41. Upon return home of the user of a system of this kind he may turn arm 95 in a counter-clockwise direction to again ensure energization of the heater at'either the start of the next off-peak period or at any other time thereafter desired by him. It may here be pointed out that the thermally-actuable heater control switch 49 is'effective to open the energizing circuit of the heater at any time during the off-peak period when all of the water in the tank is hot. v

Referring now to Fig. 6 of the drawings, I have there illustrated a modified and simplified control system effective for the same general purpose andoperating in the same general manner as the system shown more particularly in Fig. 1 of the drawings. I provide a continuously operative timing means II effective to cause closure of a switch I55 which switch is a heater control switch. This switchincludes a relatively rigid contact arm I51 and a resilient contact arm I59 normally biased out of engagement with arm I51 but moved thereinto by the portion 23 on cam 2| which, for all practical purposes, is substantially the same as hereinbefore described; I provide a main heater control switch in the form of an electro-magnetic contactor I6I oi the usual construction and including in addition to'a main contactor bridging member I63, an auxiliary contact bridging member I55, each of these contact bridging members being adapted to engage fixed contact members, all in a manner well known in the art. Contact arm I51 is connected through a conductor I91 to one of the fixed contact members engageable by bridging member I93, the other fixed contact member of this pair being connected through a conductor I69 to one terminal of the electric heater 43-the other terminal of which is connected through a conductor I1I with the supply circuit conductor 59. When the contact members of switch I55 have been moved into engagement with each other by the timer cam and if and when contact bridging member IE3 is in engagement with its cooperating fixed contact members, an energizing circuit will be closed through the electric heater 43.

I provide a manually adjustable delaying means of the same kind as hereinbefore described and including the manually adjustable arm 95, the switch including contact arms 91 and 99 and the switch including contact arms I23 and I25 but with the exception of the relay H5 and the contacts directly controlled thereby.

If it be assumed that the user of this modified system of water heatercontrol' desires to have heating of the water start at the beginning of an ofi-peak period the cam disc 83 occupying the position shown in Fig. 6 of the drawings at the start of an off-peak period, arm 95 will be positioned as shown in Fig. 6 whereby contact bars 91 and 99 are moved into engagement with each other. A circuit will therefore be closed from supply circuit conductor 6| through switch I55, a conductor I13 to arm I25 and through contact arm I23, a conductor I15 to contactarm 99, to contact arm 91, through conductor I11 and through the coil of contactor I6I and a conductor I19 to conductor HI and from there to the other supply circuit lead 59. :Ihis causes energization of the contactor ISI withresultant upward movement of contactor bridging member I63 whereby closure of the heater energizing circuit is effected. Here again it may be pointed out that closure of switch I55 energizes the rest of the system with certain hereinbefore described results.

I provide a thermally actuable switch including a relatively frigid contact arm IBI, a resilient contact arm I83 engaged by an expansion rod I85 which is mounted within a tubular member I81 the water in the lower part of the tank surrounding the tube I81. A holding circuit through the coil of contactor I6I is closed by the contact bridging member I65, this circuit being substantially as follows: From conductor I61 through a conductor I89 to contact arm IBI, to contact arm I83 if the Water ambient to the tubular member I81 is cold, through a conductor I9I to one of the fixed contact members engaged by bridging member I65, from there through a conductor I93 through the coil of contactor I6I and from there through'conductors I19 and HI to the other supply circuit lead 59. Thisholding circuit causes continued closure of the'contactor I6I with contact bridging member I63 in engagement with its cooperating fixed contact members even after the rotating cam disc 83 and particularly the projection 85 or 81 thereon, has caused opening of switch bars 91 and 99.

It may here be pointed out that if the temperature of the water ambient to tubular mem- I ber I81 is raised to a predetermined value at any time'during the off-peak period, disengagement of contact arms I83 and I8I will cause opening of the holding circuit and interruption of the heater energizing circuit by the contact bridging member I63. It is also evident that opening of the switch I55 at the end of an off-peak period will deenergize the heater circuit and restore all of the heater circuit controlparts to their initial positions.

Referring now to Fig. 7 of the drawings, I have there illustrated a modified formof water heating system embodying my invention which permits not only of a predetermined retardation or delay controllable by an operator or the user of such a water heating system but which will also permit of a prolongation of the energization of the heater and therefore continuation of the heating of the water in the tank in case all of the water in the tank is not hot at the end of an off-peak period as may happen because of withdrawals of hot water from the tank during the latter part of the oft-peak period or because of the fact that more than the usual amount of hot water had been withdrawn from the tank before the start of energization of the heater. It may be pointed out that the general result of this modified system is that in case the tank contains an appreciable amount of cold water at the end of the 'ofi-peak period, energization of the heater is continued until all of the water in the tank is hot or until the water in the lower part of the tank has been heated to a predetermined temperature.

For this purpose conductor I89, one end oi which is connected to contact arm I9I, has its other end connected to the contact arm I95 of a throw-over switch, the contact arm being adapted to selectively engage two spaced fixed contact members I91 and I99. Contact member I91 is electrically connected with conductor I13 while contact member I99 is connected by a conductor 29I with supply circuit lead BI and contact arm I59 of switch I55. An inspection of the diagram of Fig. 7 will show that if arm I95 is placed in engagement with contact member I91 there will be no prolongation of energization of the electric heater 43 beyond the end of the oil-peak period in case all of the water in the tank is not hot at the end of such off-peak period. This, of course, is because of the fact that disengagement of "contact arms I51 and I59 causes deenergization of the entire water heating system controlled thereby. If, onthe other hand, contact arm I95 is placed in engagement with contact member I99 it is evident that the holding circuit controlled, at least in part, by said contact arm I95 will continue to be energized even after disengagement of the contact arms I51 and I59 by the timing device since contact member I99 is electrically connected with the supply circuit conductor SI and in case the holding circuit for the contactor I9I is not opened by the disengagement of contact arm I83 from contact arm I9I before the end of the off-peak period because all of the water in the tank had not been heated to a relatively high temperature, energization of the heater 43 will continue until such time as disengagement of contact arm I93 from contact arm I8I is efiected because all of the water in the tank is hot, whereby the holding circuit hereinbefore described for the coil of contactor I6I is opened. As soon as all of the water in the tank is hot, after the end of an off-peak period, and the heater has been deenergized, it will not be reenergized until the start of a second off-peak period.

Referring now to Fig. 8 of the drawings, I have there illustrated a still further modification of system embodying my invention and the cam disc 2I continuously driven by the synchronous motor I3 is adapted to control an auxiliary timer switch 293 including more particularly a rela tively rigid contact arm 295 and a resilient contact arm 291 normallybiased out of engagement with contact arm 295 and moved into engagement therewith by the portion 23 of the cam disc. The manually adjustable arm 95 has mounted thereon a slightly modified form of relatively rigid contact am 299 adapted to be engaged by a resilient contact arm 2 normally biased out of engagement therewith. The arm 299 has its outer endportion bent from the general plane of the main part thereof for apurpose which will hereinafter appear. The contactor I9I is in this modification the sole circuit controlling means for the heater 43 and includes a main contact bridging member I93 adapted to cooperate with and engage and disengage fixed contact members one of which is connected to the supply. circuit lead 6| by a conductor 2I3.

while the other main fixed contact member is connected by a conductor 2I5 to one terminal of the heater 43, the other terminal of which is connected by a conductor 2" to the other supply circuit conductor 59.

Supply circuit lead BI is connected through a conductor 2I9 to contact arm 291 and contact arm 295 is connected through a conductor 22I to contact arm 2 hereinbefore mentioned. Contact arm 299 is connected through a conductor 223 with one terminal of the coil of contactor I9I the other connections being substantially as set forth herebefore in connection with particularly Fig. 6 of the drawings. Contact bar III is connected by a conductor 225 with a movable switch blade 221 adapted to selectively engage fixed contact members 229 and 23I, contact 229 being connected to conductor 22I while contact 23I is connected to conductor 2I3.

When the contact arms of switch 293 are caused to engage each other and when contact arm 2 is moved into engagement with contact arm 299 at a time predetermined by the operator and determined by the setting of the arm 95, the coil of contaotor BI is energized in the same manner as hereinbefore set forth for Figs. 6 and 1 with resultant energization of the coil and engagement of bridging member I63 with the fixed contacts whereby the heater I3 is energized at the preselected time.

If switch arm 221 was moved by the operator into the position shown in broken lines in Fig. 8, where it engages contact member 229, the heater 43 will be deenergized at the end of the off-peak period as soon as the holding circuit is deenergized.

However, if switch arm 221 is in the position shown in the full lines where it engages contact member 23I, energization of the heater 43 will continue beyond the end of the oil-peak period, in case all of the water in the tank is not hot at that time and such energization will continue until all of the water in the tank has been heated to a predetermined temperature when disengagement of contact bar I93 from contact bar I8I will open the holding circuit of the contactor with resultant opening of the main heater control switch actuated thereby and the deenergized heater 43 will remain deenergized until the start of another off-peak period.

If the user or operator desires to prevent any reenergization of the heater after it has once been deenergized, it is only necessary for him to cause turning movement of arm 95 in a clockwise direction until it engages the stop pin I5I at which time the bowed outer end of contact bar 299 engages a pin 233 suitably mounted in the casing whereby arm 299 is moved out of engagement with arm 2 even though at a a certain time, namely at the end of the off-peak period, arm 2 was in engagement with arm 299.

It is to be understood that the systems of Figs. '1 and 8 include also the manually adjustable delay means shown in Fig. 1 but shown partly only in Figs. 7 and 8.

The system embodying-my invention thus provides relatively simple, compact and easily operated means whereby the user or owner of a system of this kind can delay the start of the heating of the water in the tank for a predetermined.

and preselected length of time after the start of an oft-period, whereby he can so adjust certaln parts as to prevent reenergization thereof until these parts are manually reset to other operative positions as well as to continue the energization of the heater with'resultant accretion of hot water in the tank when-withdrawals of hot water from the tank at other hours than usual has caused the presence of appreciable quantities of cold water in the tank because of unusual demands for hot water.

While I have shown and described several modifications of systems embodying my invention it is evident that further modifications can be made without departing from the spirit and scope of the invention and I desire that all such modifications clearly coming within the scope of the appended claims shall be considered to be covered thereby.

I claim as my invention:

1. In an off-peak water heating system for a hot water tank having an electric heater, a continuously operative timing means, an intermittently operative timer including an electric motor controlled and energized by said continuously operative timing means during a predetermined portion of the day only, a plurality of switches controlled respectively by the timing means and the timer, an electromagnetic switch controlled by said plurality of switches to control the energization of the electric heater and manually-adjustable means 'for setting the switch controlled by said intermittently operative timer motor for selectively causing energization of the electric heater at the start of an off-peak period, at a later predetermined time during an oil-peak period and for preventing energization of the electric heater altogether.

2. In an oil-peak water heating system for a hot water tank having an electric heater, 2. continuously operative timing means, an intermittently operative timer including an electric motor controlled and energized by said continuously operative timing means during an ofi-peak period only of a day, aswitch adapted to be moved into and held in closed position by said continuously operative timing means during an oil-peak period, a switch adapted to be moved into closed position for a'short time by said intermittently operative timer motor, an electromagnetic switch for the heater controlled jointly by the switches controlled by the continuously operative timing means and the intermittently operative timer and manually-actuable means a for setting the switch moved into closed position for a short time by the intermittently operative timer to cause energization of the electric heater at a selectively predetermined time during the off-peak period.

3. In an off-peak water heating system for a hot water tank having an electric heater, an electromagnetic switch controlling said heater, a first switch adapted to prepare an electric control circuit for saidelectromagnetic switch, a continuously operative timer for holding said first switch in closed position during an ofi-peak period, a second switch adapted to close the electric control circuit of the electromagnetic switch to cause the latter to move to heater en ergizing position, an intermittently operative timer including an electric motor energized by said first switch for causing momentary closure of said second switch at an adjustably predetermined time during an oil-peak period to thereby cause closure of the electromagnetic switch and energization of the heater and a energization of the electromagnetic switch and efiective to cause deenergization of the electric heater when substantially all of the water-in the tank is hot irrespective of the position of said first named timer controlled switch,

4. In an oil-peak water heating system for a hot water tank having an electric heater, an electromagnetic switch controlling said heater, a first switch adapted to prepare an electric control circuit, for said electromagnetic switch, a continuously operative timer for holding said first switch in closed position during an offpeak period, an intermittently operative timer including-an electric motor energized by said first switch during an ofi-peak period only and means including a switch controlled by said intermittently operative timer, a manually-settable switch, athermally actuable switch subject to tank water temperature and electric connections between all of said switches to selectively cause energization of the heater at the start of an off peak period, to cause energization of the heater at an adjustably'predetermined time during an ofi-peak period, to cause deenergization of the heater at the end of an oiI-peak period and to cause continuation of the energization of the heater beyond the end of the oil-peak period and deenergization of the heater when substan-' tially all of the water in the tank is hot. 7 5. In an oil-peak water heating system comprising an electric tank heater, a continuouslyoperative timing means, a switch controlled by saidtiming means and adapted to be held thereby in closed position each day during an 01T- peak period, an electromagnetic switch for effecting energization of said tank heater and means for delaying energization of said tank heater after closure of said time-controlled switch, said means including an electric motor energized through said time-controlled switch, a cam disc driven by said motor, a

normally open switch controlled solely by said thermally actuableswitch controlling the de- 75' cam disc for controlling the electromagnetic switch adapted to be closed by said cam disc at a predetermined time during an off-peak period and a manually-actuable support for said last named switch to cause movement thereof relatively to the cam disc .to determine the time during the offepeak period'when the last named switch will be closed by the cam, disc to cause energization of the electromagnetic switch and consequent energization of the tank heater.

6. In an off-peak water heating system comprising an electric tank heater, an electric circuit including said electric heater, a normally open switch in said electric circuit, a continuously operative timing means for causing closing of said switch each day at the start of an oil-peak period and for holding it closed during an ofipeak period, an electromagnetic switch in said electric circuit and in series circuit relation with said time-controlled switch and acooperable therewith to control the energization of said tank heater and: manually-adjustable means for delaying energization of said electromagnetic switch and of the tank heater, said delaying means including a rotatable cam disc, an electric motor for causing rotation of said disc energized and operative only during the offpeak period and meansfor controlling the energization of said electromagnetic switch including a normally .open switch adapted to be moved manually relatively to said cam'disc to be closed therebyat a predetermined time after closure of said time-controlled switch to cause closure of said electromagnetic switch and attendant energization of the tank heater at said predetermined time.

7. A system as set forth in claim 6 and including means engaged by said manually-movable switch when moved to a predetermined forward position to prevent closure of said electromagnetic switch and energization of said tank heater irrespective of the closure or the normally-open switch by the timing means.

8. In an ctr-peak water heating system comprising an electric tank heater, a continuously operative timing means, a normally-open switch actuable by said timing means and adapted to be held thereby in closed position each day during an off-peak period of predetermined duration, an electromagnetic switch for effecting energization 01' said tank heater and manually-adjustable means for delaying energization of said electromagnetic switch and of the tank heater after the start of an oft-peak period, said delaying means including a rotatable cam disc, an electric motor electrically controlled by said normallyopen switch actuable by said timing means and energized thereby only during the off-peak period and means for controlling the energization of said electromagnetic switch including a normally open switch adapted to be moved manually relatively to said cam disc to be closed thereby at a predetermined time after closure of said timecontrolled switch to cause closure 01 said electromagnetic switch and attendant energization of the tank heater at said predetermined time.

9. A system as set forth in claim 8 and including means engaged by said manually movable switch when moved to a predetermined forward position to prevent closure of said electromagnetic switch and energization of said tank heater irrespective of the closure of the normally open switch by the timing means.

10. In an oil-peak water heating system for a hot water tank having an electric heater, heater control switching means including an electromagnetic switch and means for selectively causing movement of said electromagnetic switch to heater-energizing position at the start of an offpeak period or at any time during an off-peak period at the will of an operator including a con-' tinuously operative timer, a normally open switch actuable by said timer and adapted to be held thereby in closed position during an off-peak period, an electric motor electrically controlled by said normally open switch actuable by said timer and energized thereby only during an oil'- peak period, a second normally open switch adapted to be set manually by an operator and means actuated by said electric motor for causing closing of said second switch at a predetermined time after closure of the time-controlled.

switch according to the setting of said second switch.

11. In an oil-peak water heating system for a hot water tank having an electric heater, heater control switching means including an electromagnetic switch and means for selectively causing movement of said electromagnetic switch to heater-energizing positionat the start of an offpeak period or at any time during an oil-peak period at the will of an operator including a continuously operative timer, a normally open switch actuable by said timer and adapted to be held thereby in closed position during an ofi-peak period, an electric motor electrically controlled by said normally open switch actuable by said timer and energized thereby only during an of!- peak period, a second normally open switch adapted to be set manually by an operator, means actuated by said electric motor for causing closing of said switch at a predetermined time after closure of the time-controlled switch according to the setting of said second switch and means including a thermally-actuable switch subject to tank water temperature and a third switch manually actuable to either one of two operative positions to selectively cause energization of the heater to be terminated at the end of an oil-peak period or to continue after the end of an elf-peak period in case less than all of the water in the tank is hot at the end of an oil-peak period.

12. In an off-peak water heating system for a hot water tank having an electric heater, an electromagnetic heater control switch, a continuously operative timing means, a normally open switch adapted to be held in closed position by said timing means during an oil-peak period, an electric motor electrically controlled by said switch actuable by said timing means, a second normally open switch momentarily actuable to closed position by said motor and manually settable to be closed by said motor at a predetermined time during an oif-peak period to cause energization of the electromagnetic switch and of the electric heater.

13. In an off-peak water heating system for a hot water tank having an electric heater, an electromagnetic heater control switch, a continuously operative timing means, a normally open switch adapted to be held in closed position by said timin'g means durin an off-peak period, an electric motor electrically controlled by said switch actuable by said timing means, a second normally open switch momentarily actuable to closed position by said motor and manually settable to be closed by said motor at a predetermined time during an ofl-peak period to cause energization of the electromagnetic switch and of the electric heater and means including a thermallyactuable switch subject to tank water temperature and a third switch manually actuable to either one of two operative positions to selectively cause energization of the heater to be terminated at the end of an ofi-peak period or to continue after the end of an oil-peak period in case less than all of the water in the tank is hot at the end of an oil-peak period.

CLARK M. OSTERHELD. 

